What ‘unstoppable’ Antarctic ice melt means for Western cities

Save for a freak May snowstorm, the other day started off normally. I woke up, made a giant mug of coffee and walked to work. But May 12 was no ordinary Monday. “Today,” said Eric Rignot, a glaciologist at the University of California, Irvine, “we present observational evidence that a large sector of the West Antarctic Ice Sheet has gone into irreversible retreat. It has passed the point of no return.”

Language that strong isn’t often tossed about at NASA news conferences, and the world took notice. Climate change advocate Protect Our Winters called it “the day that all climate scientists feared.” Mother Jones coined it a “holy shit moment for global warming.” The well-known Canadian environmental writer Chris Turner tweeted that it’s “the most important news story you'll see this week, by a wide margin.”

So what’s all the fuss about – and why should you care? In the most basic terms, two separate scientific studies, using two different models and released by two reputable scientific journals, both came to the same conclusion: Glaciers on the West Antarctic Ice Sheet are melting more rapidly than expected and have begun a domino effect that’s virtually unstoppable, even if we cut off greenhouse gas emissions today. Over the course of hundreds of years, the melting glaciers will boost ocean levels by 4 to 16 feet, changing the geography of the world as we know it.

Previous models, of course, have also predicted sea level rise, and West Coast cities have begun preparing by relocating threatened structures, moving drinking water supplies and modifying construction permits. But no previous study has been this conclusive or concrete in its modeling, nor taken into account the degree of Antarctic melt now considered inevitable. The Intergovernmental Panel on Climate Change (IPCC) warned earlier this year that global sea level could rise between four inches and three feet by 2100, but the new findings make such predictions seem almost quaint. Penn State University geoscientist Sridhar Anandakrishnan told NBC News that future IPCC estimates “will almost certainly be revised” upwards as a result of the new studies.

What could rising seas actually look like for the West Coast? Andrew David Thaler, a deep-sea ecologist, posed that question to his Twitter followers last fall, and the response was tremendous: Requests poured in from around the world asking Thaler to virtually inundate their hometowns under the hashtag #DrownYourTown. #DrownYourTown has now been tweeted millions of times, and Thaler has perfected a real-time, interactive GIS modeling technique that allows him – or anyone with basic technology skills – to visualize what coastal cities might look like with varying amounts of sea level rise.

Thaler warns that the images aren’t exact and shouldn’t be used to make real estate decisions. But with once-theoretical sea level rises now a looming reality, these images make the future of the West Coast graspable. Here are a few we found particularly unsettling. (Click images to enlarge.)

1. If the West Antarctic Ice Sheet completely melted into the Amundsen Sea – as the new studies from NASA, UC Irvine and the University of Washington predict will eventually happen – the resulting 16 feet of sea level rise would look like this:

Honolulu, Hawaii

Marin City, California

Waldport, Oregon

Tacoma, Washington

Sitka, Alaska

South Padre Island, Texas

2. Here’s downtown San Francisco with 22 feet, the rise that would occur if the entire Greenland Ice Sheet melted (a scenario not part of the new studies):

3. And, just for kicks, a couple of cities with 32 feet sea rise:

Vancouver, British Columbia

San Diego, California

4. Yeah, yeah, you’re saying. My great-grandkids won’t even be alive for that. How about something more immediate?

The new studies don’t make predictions for specific years, so the best we can do for the end of this century – the year 2100 – is the IPCC’s latest estimate of about 4 feet sea level rise. Keep in mind that figure may be conservative, as scientists now say the IPCC estimates will likely increase in light of to this new information. Either way, here are a couple non-Western spots with about 3 feet sea level rise:

North Carolina coast

Key West, Florida

5. You want something more immediate, you say? Ok: The village of Newtok, Alaska, 480 miles west of Anchorage, has already experienced severe flooding and erosion and is expected to be underwater by 2017. Its 350 residents – called “America’s first climate refugees” by some media outlets – are trying to scrounge up the $130 million needed to move their village upriver.

All images courtesy #DrownYourTown.Krista Langlois is an editorial fellow at High Country News. She tweets @KristaLanglois2.

More from Climate Change

You might want to do a bit of research in which you will discover Antarctic sea ice is at record extent by satellite monitoring. As reported by the National Snow & Ice Data Center:

"In the Southern Hemisphere, autumn is well underway, and sea ice extent is growing rapidly. Antarctic sea ice extent for April 2014 reached 9.00 million square kilometers (3.47 million square miles), the largest ice extent on record by a significant margin. This exceeds the past record for the satellite era by about 320,000 square kilometers (124,000 square miles), which was set in April 2008."

As my old Professor in grad school used to say, "reading the literature should always come before writing the literature on a research topic"

Andrew V Sipocz

May 16, 2014 04:11 PM

Yes, but this is floating sea ice that forms and melts each year. The article is talking about ice sheets sitting on land. When floating sea ice forms or melts it doesn't alter sea level as it displaces its own mass as do ice cubes in a glass of water. When the ice sheets of west Antarctica melt they will raise sea level over 10'. Scientists are sure why the winter sea ice is increasing around Antarctica but some articles hypothesize that the same increasing winds that are pushing warm ocean water against the grounded ice sheets and is melting them (from underneath), are also allowing more floating sea ice to form as they push the ice further out to sea making room for more to form. Another idea is that the increasing air temperature and warming seas around Antarctica hold more water and thus increase precipitation (snowfall is increasing) which freshens the sea surface water (the sea around Antarctica is stratified by salinity and temperature) and thus allows more ice to form (freshwater freezes at higher temps than does saltwater). Both the winds and warming are linked to global warming. Sounds counterintuitive that a warming world would produce more floating sea ice, but there you go. You have to go where the science leads you even if it plays with your mind like a cat with a ball of yarn.

Krista Langlois

May 20, 2014 10:40 AM

Hi Andrew - thanks for clarifying. Yes, the recent studies referenced in this blog refer to land ice, not floating sea ice: Two very different entities. For more explanation, Jack, check out this link: http://www.nasa.gov/[…]/#.U3I_Jyh0GhE

Andrew V Sipocz

May 20, 2014 01:53 PM

Ugh. More bad news this week makes the crazy "future pics" in this story more likely than not to occur for real. New research shows that the Greenland Ice Sheet has some of the same "soft underbelly" problems as the West Antarctic Ice Sheet as does portions of the East Antarctic Ice Sheet. I also read an interview of Eric Rignot in which he elaborated on the timing of this and although his article talks of a time frame for calamity as being somewhere between 200 and 1,000 years, it's more likely to be around 200 years. Well within the planning horizon for us humans.